The present invention relates generally to gas turbine airfoils, and more particularly to a system and process for testing resonant frequencies of such airfoils.
Airfoils interact with working fluid flow in gas turbine engines. Resonance conditions in such engines can cause damage or otherwise reduce part lifetimes. To prevent damage from harmful resonance conditions, airfoil assemblies (e.g. stages of blades and vanes) are designed to avoid natural frequencies experienced by parts during normal operation.
For each part, manufacturing tolerances typically produce airfoils having a range of resonant frequencies. During engine design, the resonant frequencies of airfoils are sometimes manually tested to ensure that harmful resonance conditions can be avoided. Manual testing systems and methods used during part design are slow, and are not suited to testing a high volume of airfoils during manufacture. Batch testing of a small sample of manufactured airfoils may be inadequate in cases where small variations in airfoils within manufacturing tolerances produce significant effects on assembled blade structures.